The ATP on Monday crowned Andy Murray king of the tennis world but the Scot must now plot how to stop Novak Djokovic grabbing back the number one place at the Tour Finals.

The 29-year-old Murray -- the oldest player to become number one for the first time -- won the Paris Masters on Sunday and immediately headed back to London to prepare for the finals.

File image of Andy Murray. AFP

"It might only be for one week. So I might as well try and enjoy it because I could lose it at the Tour Finals and never be there again," said Murray.

Murray, who beat American John Isner 6-3, 6-7 (4/7), 6-4 in Paris for his eighth tournament win of the year and fourth in a row, should be top for at least two weeks.

Murray is 405 points above Djokovic in the new rankings. The Serb -- who had been number one for 122 weeks before losing his Paris quarter final -- could go top again if he lands a fifth straight Tour Finals crown.

"I wasn't thinking so much about the cushion or anything like that at the top. I'm obviously happy I got there. It would be nice to finish the year No. 1, but I'm happy that I managed to get there," said Murray.

The Scot has struggled at the London finals, exiting at the round robin group stage twice after missing the 2013 event through injury.

"The last couple of years have been tough there for me. So, yeah, obviously I want to try and play my best tennis there.

"It's not necessarily about winning. I just want to play my best and finish the year on a good note in that respect, because some of the years it has been tough for me there.

"So hopefully I can play some good tennis there. I will take a few days' break now, and rest up a little bit and get ready for one big push out of the next 10 days."

Melbourne motivation

With Roger Federer -- who dropped out of the top 10 for the first time in 14 years -- and Rafael Nadal both sidelined, and Djokovic short of his best, Murray will head into next season with lofty expectations.

"Obviously I'd love to win the Australian Open because it's sort of the next major goal, beginning of next year, because I have been close a number of times and I have never quite done it," he said.

But the five-time Melbourne finalist ruled out looking too far ahead, pointing to his own rapid rise as evidence of how quickly circumstances can change.

"I'll sit down with my team and basically look at what my schedule is going to be for the beginning part of next year and set goals through to March time probably, because I have found that I have worked better when I have had more short-term goals.

"So much can happen and change in a small space of time as I have found out a number of times during my career.

"These last few months no one would have expected what I have done the last few months in the summer, really, or after the French Open. So this was unexpected to me, as well. I didn't expect it."

Murray's Paris victory means the 'Big Four' have now won 56 of the last 61 Masters events dating back to Monte Carlo in 2010, but the Scot's return of just three Grand Slam titles leaves him well short of his rivals.

Isner backed Murray to significantly add to that tally before his time is up.

"He's the guy that everyone is looking up to right now," said Isner.

"Whether it's 2, 3, 4 in the world, everyone knows how hard he works and how dedicated he is."